It is generally well known that conduits or pipes, particularly underground pipes, which are employed for conducting fluids, for example, sanitary sewer pipes, storm sewer pipes, water lines and gas lines, frequently require repair due to fluid leakage. The leakage may be inwardly, from the environment into the interior or conducting part of the pipe, or outwardly, from the conducting part of the pipe into the surrounding environment. Leakage of this type may be due to improper initial installation of the pipe, deterioration of the pipe itself due to normal aging or the effects of conveying corrosive or abrasive materials, cracking of the pipe or pipe joints due to environmental conditions, such as earthquakes, the movement of large vehicles or similar natural or man-made vibrations, or any other such causes. Regardless of the cause, such leakage is undesirable, at best, and may result in waste of the fluid being conveyed by the pipe, damage to the surrounding environment and the possible creation of dangerous public health hazards.
Because of ever increasing labor and machinery costs, it is becoming increasingly more difficult, at least economically, to dig up and replace underground pipes or portions or sections of such underground pipes which may be leaking. As a result, various methods have been devised for the in situ repair or rehabilitation of existing pipes, thereby avoiding the expenses and hazards associated with digging up and replacing the pipes or pipe sections.
Briefly, in the conventional processes for the in situ repair or rehabilitation of existing pipes, an elongated flexible tubular liner comprised of a felt fabric or foam or similar flexible material, which has been impregnated with a thermosetting synthetic catalyzed resin is installed within the existing pipe utilizing an inverting or everting process, as is known to those skilled in the art. Once the flexible liner is installed in place within the pipe, the liner is pressurized from within, preferably utilizing a fluid such as water, to force the liner radially outwardly to engage and conform to the interior surface of the pipe and to force some of the impregnated resin into any cracks or interstices within the walls of the pipe. The resin is then cured to form a relatively hard, tight fitting, rigid pipe lining which effectively seals any cracks and repairs any pipe or pipe joint deterioration to prevent further leakage either into or out of the pipe. The cured resin liner also serves to strengthen the existing pipe walls to provide added structural support for the surrounding overburden.
The conventional processes for the installation of a liner within the interior of a pipe are problematic in that they are limited to a pipe having a leading end and a trailing end, wherein the leading and trailing ends are directly or easily accessible. That is, the conventional processes have been limited to installing liners within, for example, main sewer pipes which typically are installed underground beneath a street or road in a residential or commercial area and are easily accessible through existing manholes. One device for installing a liner in such a main sewer pipe is disclosed in U.S. Pat. No. 4,685,983, issued to Charles A. Long, Jr. and assigned to Long Technologies, Inc., which is hereby incorporated by reference.
Typically, the main sewer pipe is in fluid communication with each house or building in the residential or commercial area for receiving sewage therefrom and transporting the sewage to a treatment center. A service pipe is transversely connected to the main pipe, for instance, at a wye connection, and provides the means for transporting the sewage to the main pipe, as is understood by those skilled in the art. After a liner has been installed within the main pipe as described above, a conventional robot cutter apparatus such as the apparatus disclosed in U.S. Pat. No. 4,630,676, issued to Charles A. Long, Jr. and assigned to Long Technologies, Inc., is deployed within the main pipe for cutting a portion of the liner in the area where the service pipe meets the main pipe for allowing fluid within the service pipe to flow into the lined main pipe.
While much effort and expense has been expended to reconstruct main sewers, interceptor sewers and trunk sewers, there now exists a need for an effective and economical method for reconstructing service pipes which extend between commercial or residential buildings and the main sewer pipe. The present invention is directed to a service pipe which has been located near the building or private property line and wherein the service pipe includes a clean-out fitting proximate the property line, as is understood by those skilled in the art. While it is preferred that the main sewer first be reconstructed with a new liner and cut away at each of the service connections, the present invention of installing a liner within the service pipe is not limited thereto.
The present invention overcomes many of the difficulties inherent in the prior art liner installation method by providing a flexible tubular liner which can be installed from just one end of a service pipe. That is, the liner of the present invention can be installed within a service pipe without having to directly access both ends of the pipe. The present invention includes a flexible tubular liner having a flexible retainer secured thereto which is positioned through the clean-out fitting of the service pipe, through the service pipe and into the main pipe proximate the service pipe terminal end for preventing the flexible tubular liner from moving into the service pipe. Consequently, the present invention provides considerable savings economically by avoiding the necessity of having to dig up or replace underground service pipes which may be leaking or damaged.